The effect of seprafilm and interceed on capsule formation around silicone discs in a rat model

Anti-adhesive effect of chondrocyte-derived extracellular matrix surface-modified with poly-L-lysine (PLL)

After an injury, soft tissue structures in the body undergo a natural healing process through specific phases of healing. Adhesions occur as abnormal attachments between tissues and organs through the formation of blood vessels and/or fibrinous adhesions during the regenerative repair process. In this study, we developed an adhesion-preventing membrane with an improved physical protection function by modifying the surface of chondrocyte-derived extracellular matrices (CECM) with anti-adhesion function. We attempted to change the negative charge of the CECM surface to neutral using poly-L-lysine (PLL) and investigated whether it blocked fibroblast adhesion to it and showed an improved anti-adhesion effect in animal models of tissue adhesion. The surface of the membrane was modified with PLL coating (PLL 10), which neutralized the surface charge. We confirmed that the surface characteristics except for the potential difference were maintained after the modification and tested cell attachment in vitro. Adhesion inhibition was identified in a peritoneal adhesion animal model at 1 week and in a subcutaneous adhesion model for 4 weeks. N-CECM suppressed fibroblast and endothelial cell adhesion in vitro and inhibited abdominal adhesions in vivo. The CECM appeared to actively inhibit the infiltration of endothelial cells into the injured site, thereby suppressing adhesion formation, which differed from conventional adhesion barriers in the mode of action. Furthermore, the N-CECM remained intact without degradation for more than four weeks in vivo and exerted anti-adhesion effects for a long time. This study demonstrated that PLL10 surface modification rendered a neutral charge to the polymer on the extracellular matrix surface, thereby inhibiting cell and tissue adhesion. Furthermore, this study suggests a means to modify extracellular matrix surfaces to meet the specific requirements of the target tissue in preventing post-surgical adhesions. This article is protected by copyright. All rights reserved.

The effects of human amniotic membrane on silicone related capsule formation in rats

Silicone breast implants are commonly used materials in plastic surgery for breast augmentation and reconstruction and the most severe complication of silicone implants are capsule contraction which occurs in 40% of patients. The aim of our study is to evaluate how the amniotic membrane alters the capsule formation effects of silicone 24 wistar rats were used in the study. We placed a bare silicone block into the left side (Subgroup A) and single layer amniotic membrane coated silicone block into the right side (Subgroup B) of the rats back. The rats were then separated into three groups and in group 1 rats were euthanized after 3 weeks, in group 2 after 12 weeks and in group 3 after 24 weeks. Then capsule thickness, fibroblast and lymphocyte cell counts were evaluated for each sample. In Group 2 and group 3, the capsule thickness in Subgroup B was detected to be statistically significantly lower than that in Subgroup A. In Group 1, 2, and 3, the lymphocyte count in the capsule tissue taken from Subgroup B was lower than Subgroup A but the difference was not statistically significant. In Group 2 and 3, the fibrocyte count detected in the capsule tissue in Subgroup B was found to be statistically significantly lower than Subgroup A. the amniotic membrane was demonstrated to reduce capsule thickness by the antifibrinolytic effect in our study.

Silicone breast implant modification review: overcoming capsular contracture

Background

Silicone implants are biomaterials that are frequently used in the medical industry due to their physiological inertness and low toxicity. However, capsular contracture remains a concern in long-term transplantation. To date, several studies have been conducted to overcome this problem. This review summarizes and explores these trends.

Main body

First, we examined the overall foreign body response from initial inflammation to fibrosis capsule formation in detail and introduced various studies to overcome capsular contracture. Secondly, we introduced that the main research approaches are to inhibit fibrosis with anti-inflammatory drugs or antibiotics, to control the topography of the surface of silicone implants, and to administer plasma treatment. Each study examined aspects of the various mechanisms by which capsular contracture could occur, and addressed the effects of inhibiting fibrosis.

Conclusion

This review introduces various silicone surface modification methods to date and examines their limitations. This review will help identify new directions in inhibiting the fibrosis of silicone implants.

The Effects of Colchicine-Impregnated Oxidized Regenerated Cellulose on Capsular Contracture

Capsular contracture is the most common complication of breast augmentation. Oxidized regenerated cellulose can be used as a matrix for drug transport. Colchicine is an antimitotic drug that interferes with various steps of wound healing. The aim of this study was to evaluate the effects of oxidized regenerated cellulose alone or in combination with colchicine on capsular contracture. Twenty-one adult female Wistar-Albino rats were divided into 3 groups. In group 1 silicone blocks only, in group 2 oxidized regenerated cellulose-wrapped silicone blocks, and in group 3 colchicine-impregnated oxidized regenerated cellulose-wrapped silicone blocks were inserted in the dorsal region. Four weeks later, implants were removed and histopathological examination was performed. Capsular thickness, inflammatory infiltrate degree, collagen fiber organization, and myofibroblast density were evaluated. Macroscopic examination revealed a distinct capsule formation only in group 1 animals, with average measurement being 134.65 µm on histopathological examination. In groups 2 and 3 animals, no distinct capsule formation was seen. Inflammatory infiltrate degree was found to be less in groups 2 and 3 animals than in group 1 animals. Collagen fiber organization around the implants was found to be parallel and organized in group 1 animals, whereas it was random and disorganized in animals in both groups 2 and 3. High myofibroblast density was observed in animals in groups 1 and 2, while no myofibroblast was found in animals in group 3. The results of our study suggest that coating silicone implants with oxidized regenerated cellulose or with colchicine-impregnated oxidized regenerated cellulose may be effective in preventing capsular contracture.

The pathology of the foreign body reaction against biomaterials

The healing process after implantation of biomaterials involves the interaction of many contributing factors. Besides their in vivo functionality, biomaterials also require characteristics that allow their integration into the designated tissue without eliciting an overshooting foreign body reaction (FBR). The targeted design of biomaterials with these features, thus, needs understanding of the molecular mechanisms of the FBR. Much effort has been put into research on the interaction of engineered materials and the host tissue. This elucidated many aspects of the five FBR phases, that is protein adsorption, acute inflammation, chronic inflammation, foreign body giant cell formation, and fibrous capsule formation. However, in practice, it is still difficult to predict the response against a newly designed biomaterial purely based on the knowledge of its physical-chemical surface features. This insufficient knowledge leads to a high number of factors potentially influencing the FBR, which have to be analyzed in complex animal experiments including appropriate data-based sample sizes. This review is focused on the current knowledge on the general mechanisms of the FBR against biomaterials and the influence of biomaterial surface topography and chemical and physical features on the quality and quantity of the reaction. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 927-940, 2017.

Biomedical implant capsule formation: lessons learned and the road ahead

Clinicians and investigators have been implanting biomedical devices into patients and experimental animals for centuries. There is a characteristic complex inflammatory response to the presence of the biomedical device with diverse cell signaling, followed by migration of fibroblasts to the implant surface and the eventual walling off of the implant in a collagen capsule. If the device is to interact with the surrounding tissues, the collagen envelope will eventually incapacitate the device or myofibroblasts can cause capsular contracture with resulting distortion, migration, or firmness. This review analyzes the various tactics used in the past to modify or control capsule formation with suggestions for future investigative approaches.

Prevention of capsular contracture with Guardix-SG(®) after silicone implant insertion

BACKGROUND

Capsular contracture is the most common side effect of breast implant insertion and the problem that breast surgeons seek to avoid the most. Previous animal studies have proved that an antiadhesive barrier solution (AABS) prevents peri-implant capsule formation. In this study, the authors sought to explore the effect that Guardix-SG(®), an AABS that can encapsulate implants in the form of a gel, can have on capsular contracture.

METHOD

This study used 12 female New Zealand white rabbits weighing 2.5-3 kg. Implants were inserted into the subpanniculus carnosus plane through an incision in the bilateral midback area. Once the implant was inserted, 3 g of Guardix-SG(®) and normal saline were instilled into the left and right sides, respectively. The rabbits were killed 6 months after the procedure. The intracapsular pressure was measured using tonometry with a 38.2-g circular glass piece, and capsular thickness was measured by dyeing the biopsy specimen with hematoxylin and eosin and Masson's trichrome stain. The myofibroblasts were quantitatively analyzed through monoclonal anti-alpha smooth muscle actin antibody immunohistochemistry staining.

RESULTS

The intracapsular pressure in the control group (4.51 ± 0.98 mmHg) was significantly higher (p = 0.002) than in the study group (3.51 ± 0.4 mmHg). The average capsular thickness was significantly greater in the control group (0.33 ± 0.15 mm; p = 0.015). In the analysis, the interrelation between capsular thickness and intracapsular pressure was insignificant in both groups, as was the number of myofibroblasts in both groups (p = 0.582).

CONCLUSION

Through this study, the authors were able to demonstrate that capsular contracture can be suppressed in the rabbit model by instilling Guardix-SG(®) after insertion of cohesive gel implants in the subpanniculus carnosus plane.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Efficacy of antiadhesion barrier solution on periimplant capsule formation in a white rat model

Antiadhesive barrier solution (AABS) has been proven to prevent intraabdominal adhesion by reducing inflammation and fibrosis formation. Because this mechanism can also be applied to capsule formation after the breast implant insertion, we hypothesize that AABS can reduce capsular contraction and evaluate the efficacy of AABS on perisilastic implant capsule formation after submuscular insertion. A silicone block was inserted beneath the panniculus carnosus muscle in 10 rats. The experiment group received 0.1 mL of AABS (Guardix, Hanmi Medical Co.) instilled into the pocket, whereas the control group received 0.1 mL saline solution. Periimplant capsules were excised after 4 weeks and were evaluated for inflammatory cell count, capsular thickness, collagen pattern, and amount of myofibroblast. The inflammatory cell count and the capsular thickness were lower in the experiment group than in the control group (P < 0.05). The collagen pattern was loose and parallel in the experiment group, and the amount of myofibroblast was much less compared with the control group. AABS reduced the amount of inflammatory cells, myofibroblast, and capsular thickness. It also made the collagen fibers in the capsule loose and parallel. Therefore, AABS seemed to be effective in reducing the periimplant capsule formation.

Assessment of the efficacy of absorbable adhesion barriers on dissection in esophagus operations

OBJECTIVE

During childhood, recent repeated operations for esophagus are normally conducted if long gap esophageal atresia exists. During multistaged extrathoracic esophageal elongation procedure, the dissection of the esophagus poses severe problems due to adhesion. However, Gore-Tex membrane may simplify esophagus dissection. The most popular adhesion barriers used today are sodium hyaluronate (Seprafilm; Genzyme Corp., Cambridge, MA) and oxidized regenerated cellulose (Interceed; Johnson&Johnson Medical Inc., New Brunswick, NJ). The purpose of this study is to investigate the efficacy of adhesion barriers on esophagus dissection.

METHODS

In the study, 21 Wistar albino adult male rats were worked on. The rats were randomly divided into three groups, each including seven rats. About 1cm-segment of the esophagus, located just behind the trachea, was dissected from the surrounding tissues through blunt dissection. Rats in group 1 were wrapped with Seprafilm, and in group 2 with Interceed. But the rats in group 3 underwent only esophagus dissection. Three weeks later, during esophagus dissection, adhesion scoring was performed and esophagus was divided into two parts: one for the assessment of hydroxyproline level, and the other for histological examination.

RESULTS

When the adhesion scores of the three groups were compared, there was not a significant difference between the groups (p=0.75). In terms of tissue hydroxyproline levels, mean scores of hydroxyproline revealed no significant difference between the three groups (p=0.19). When the histopathological results were examined, esophagus looked normal and no connective tissues were seen around esophagus.

CONCLUSION

Seprafilm and Interceed had no effect on esophagus dissection. Although Seprafilm had the best mean score, this was statistically insignificant. Gore-Tex might play a better role than Interceed in preventing adhesion formation; however, it is still not certain whether adhesion barrier should be used in such organs as esophagus having no serosa.

Voies de recherche pour la mise au point de nouvelles prothèses mammaires

Despite the improvement of breast implant quality across the last decade, the perfect implant does not exist. Therefore research should manage to improve those implants. In this article we have tried to identify different directions to investigate for better prosthesis: improvement of the shell, the filling and the form. Moreover, other targets as fat transfer or other permanent soft tissue filler also need further experimental and clinical investigation.